That method of fighting the disease is different from Cerezyme, the first Gaucher medicine, which replaces an enzyme deficiency.

“The surprise is that this has proven remarkably similar to [Cerezyme] in its effectiveness, and it has the convenience of being a pill,” said Genzyme president David Meeker.

Genzyme, a division of French drug giant Sanofi SA, was a pioneer in drugs that fight rare diseases, especially enzyme replacement therapies. Gaucher disease is an inherited condition affecting fewer than 10,000 people worldwide.

The disease can cause enlargement of the liver, anemia, excessive bleeding and bruising, and bone disease in patients.

Advertisement

Genzyme expects many patients who use Cerezyme, typically taken through two-hour infusions every two weeks, may gravitate to Cerdelga, which most patients will take twice a day but a small group will take once a day.

Some patients fearful of forgetting to take the pills may prefer to continue the infusions, and some taking other Gaucher therapies, marketed by Shire PLC of Lexington or Israel’s Protalix BioTherapeutics, may switch to Cerdelga.

“Our overall Gaucher opportunity will increase,” Meeker said. “We believe strongly that if you do the right thing medically, the business model will work. We will cannibalize Cerezyme. We will for sure take some share from other companies. We are indifferent to whether patients take one drug or another. We want to create a meaningful choice for patients and doctors.”

The approval of Cerdelga raises the question of how the pill will be priced relative to Cerezyme, which costs about $300,000 annually per patient on average. Genzyme said it has yet to determine the price, but executives say it will likely be at “parity” with Cerezyme.

Drug makers often seek to develop oral therapies to complement their injectable drugs as a way to protect their franchise, said Glen Giovannetti, the Boston-based global biotechnology leader for accounting and consulting firm Ernst & Young. Biogen Idec Inc., another Cambridge company that previously sold two injectable drugs for the neurodegenerative disease multiple sclerosis, added the pill Tecfidera to its MS portfolio last year.

Advertisement

“Most people would prefer to take a pill than stick themselves with a needle,” Giovannetti said, noting drug makers also benefit from new patents that promise additional years of sales if and when low-cost injectable generic drugs enter the market. “But companies that move to orals will have to demonstrate to payers that any extra cost has value in terms of better outcomes for patients and better health that lowers overall medical costs.”

Cerdelga won’t be the first oral therapy to treat Gaucher disease. US regulators in 2003 approved Zavesca, a pill developed by Swiss drug maker Actelion Pharmaceuticals AG. But the capsule has captured only a small share of the market because it has been prescribed primarily for Gaucher patients who can’t tolerate enzyme replacement therapies.

Genzyme, which won FDA approval for Cerezyme in 1991, started working on an oral Gaucher treatment in 1999, licensing a molecule from the University of Michigan. The compound has been tested in more than 400 patients in 29 countries, in what company executives have called the largest clinical development program for any rare disease medicine.

An application for Cerdelga’s approval is also before European regulators, and Genzyme expects a decision by the end of the year. While the European Commission approves drugs for most countries, pricing decisions are more fragmented among its members.

“We are working very actively to give them a holistic view of the therapeutic value” of Cerdelga, said Carlo Incerti, the company’s Italian-based head of global medical affairs.